Ribosome precisely structured for cell growth

Optimization for self-production may explain key features of ribosomes, the protein production factories of the cell, reported researchers from Harvard Medical School in Nature on July 20.

In a new study, a team led by Johan Paulsson, professor of systems biology at Harvard Medical School, mathematically demonstrated that ribosomes are precisely structured to produce additional ribosomes as quickly as possible, in order to support efficient cell growth and division.

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Ribosomes are composed of a puzzlingly large number of different structural proteins — anywhere from 55 to 80, depending on organism type. These proteins are not just more numerous than expected, they are unusually short and uniform in length. Ribosomes are also composed of two to three strands of RNA, which account for up to 70 percent of the total mass of the ribosome.

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“An analogy for our findings would be to think of ribosomes not as a group of carpenters who merely build a lot of houses, but as carpenters who also build other carpenters,” Paulsson said. “There is then an incentive to divide the job into many small pieces that can be done in parallel to more quickly assemble another complete carpenter to help in the process.” Paper.(paywall) – Shlomi Reuveni, Måns Ehrenberg, Johan Paulsson. Ribosomes are optimized for autocatalytic production. Nature, 2017; 547 (7663): 293 DOI: 10.1038/nature22998 More.

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Note: Posting light till this evening due to O’Leary for News’s alternate other day job.

8 Responses to Ribosome precisely structured for cell growth

I’ve been studying recent findings about neurology while building courseware for a neuro book. Each of these findings literally STUNS me with the complexity and perfection of purpose.

Here’s another carpentry crew at work. During fetal development the layer of epithelium around the primitive neural tunnel produces several types of specialized cells. First it produces a few million ‘radial glia’, which grow long fibers leading out to the area where the cortex needs to form. Then it produces a few billion neurons, which CLIMB UP THE LADDERS of the radial glia until they settle in their proper locations in the cortex.

The critical word here is “optimization.” Sir Fred Hoyle starts out his book on the Mathematics of Evolution by forming a simple ‘feedback equation,’ of logrithmic growth.

He says that many people see this simple equation as representing the entire idea of “evolution”: it’s an ‘optimization’ problem, and, with a basic equation, this ‘optimization’ should take no more than 37 generations (IIRC). He then adjusts this formula to ‘normalize’ population sizes–that is, that population size stays roughly the same over the years. When he does this, suddenly the number of generations for ‘optimization’ jumps into the hundreds, if not thousands.

From a ‘design’ perspective, we correctly view what’s going on with the ribosome: it’s operating under a constraint: too big, and it takes too long to duplicate; too small, and it won’t have sufficient information.

We see this “optimization” as representing simple ONE ‘constraint’ upon zillions of others. And we understand that all of this diminishes the possibility of life arising from an underground vent, or a ‘mud pool.’

There’s no bringing the Darwinists around. They’ve seen the word they’re looking for: “optimization.” You might just have said: “Evolved.”

They’re smacking their lips. If you want to be a Darwinist, you have to know the right words.